1. Technical Field to Which the Invention Belongs
The present invention relates to a vehicle control system for controlling the vehicle speed and/or a driver warning device of a subject vehicle by detecting the road shape ahead of the subject vehicle on the basis of road data, to thereby decide whether or not the prevailing vehicle speed allows the vehicle to safely pass a curve ahead.
2. Discussion of Relevant Art
In Japanese Patent Application Laid-Open No. 60-89298, there is disclosed a well known technique through which it is decided whether or not the subject vehicle can pass a curve ahead thereof in its running direction at the prevailing speed by estimating the radius of curvature of the curve on the basis of the road data obtained by a navigation system, so that a warning can be issued to the driver if it is decided that the curve is not passable.
When so passing a curve, the range of the road ahead, as can be recognized without fail by the driver, seriously changes depending upon the vehicle speed, the weather and the curving direction so that the mental allowance for the driver accordingly changes. In the aforementioned known technique, however, what is done is to decide whether or not the prevailing vehicle speed allows passage of the curve, but no consideration is taken into the mentality of the driver. As a result, the issued warning may irritate the driver, and similarly if excessive speed control is automatically effected it may irritate the driver or its discrepancy may give the driver an uncomfortable feeling.